What is the difference between an allergy and a cold?

Colds are caused by hundreds of different viruses. When one of these viruses gets into your body, your immune system attacks. Some of the effects of this immune response are the classic symptoms of a cold, such as congestion and coughing.

The germs that cause colds are contagious. You can pick them up when an infected person sneezes, coughs, or shakes hands with you. After a couple of weeks, at the most, your immune system fights off the virus and you stop having symptoms.

Allergies are caused by an overactive immune system. For some reason, your body mistakes harmless substances—such as mold or pollen—for germs and attacks them. Your body releases chemicals such as histamine, just as it does when fighting a cold. This can cause swelling in your nasal passages, a runny nose, coughing, and sneezing. Allergies are not contagious, although some people may inherit a tendency to develop them.

The most telling distinction between Cold and Allergy are:
presence of cough, sore throat and yellow mucus for cold. Allergy typically presents a runny nose with clear mucus.

Whatever “medications” you take for a cold are palliative only, and not good for a “cure”. You can’t cure either of these maladies with over-the-counter medications; all you can do is take something that soothes your symptoms (palliative, in a word).

So take whatever makes you feel better, or just call in sick, close the bedroom door, get a good book and alternate reading and sleeping all day.

Chicken soup is supposed to be good, too. But chicken soup is good any time.

When it is allergy your mucous is clear. If you have an infection the mucous is usually green or yellow. You may need an antibiotic. Colds often come with a mild fever. A cold is a virus and requires no antibiotic. You may also have an upset stomach and some body aches. Allergy comes with itchy eyes and throat. My nose runs a lot from allergies. My nose will burn from allergy and I will sneeze constantly.

A cold lasts a week. Honestly if you are congested take a decongestant, it doesn’t really matter why. A combination decongestant antihistimine will probably be the most effective. If you are “sick” for weeks, because maybe you are allergic to pollen or dust or whatever then you would take a daily antihistamine.

If this all started with a sore throat and no congestion, and then within 48 hours the sore throat was gone and then you became congested, it is a cold for sure. You are contagious, don’t get others sick.

For your purposes, it doesn’t really matter which you have at the moment. Treat your symptoms and you’ll feel better. If your symptoms last longer than a week, then you’ll know to check into allergies.

Just to clarify @philosopher statment slightly, if it is a bacterial infection mucous is green. If it is a virus, like a cold, your mucous is clear or white. And, as he said, you don’t need an antibiotic for a virus. If you have a high fever it is more likely a bacterial infection, but I am guessing you don’t or you would not have asked if it might be an allergy.

If you are in the northerm hemisphere and have not been exposed to something new in your environment, like a new cleaning product, or a new pet, or you are staying away from home, then I say you are sick. Not too much is blooming right now.

@JLeslie
Hi I am a Women.
I want to be sure people only take antibiotics for bacterial infections.
My colds often set off my allergies and I too feel unsure sometimes..
Benadryl helps with allergy symptoms. It will relieve cold symptoms but Nyquil works better.

@philosopher I agreed with you. No antibiotics unless green.

Honestly, I think you are getting sick if it lasts a week. I don’t think an allergy triggered it. I here this all of the time and it annoys me, because those people are going around saying, “oh it’s just allergies I am not contagious.” I can understand why it might be tricky during your allergy season, or if you are allergic all year to something. If it is the winter, and you are allergic during ragweed, I don’t understand the mystery? There is an off chance of a brief exposure to something, and you might feel like you are a getting a cold, but then it lasts a day, that was probably an allergy. Better to err on the side of not giving it to everyone and sleep in the guest room I say.

@philosopher Maybe you are referring to what I said about high fever? Because you mentioned flu symtoms like achy body. When you have a cold this is very rare. Colds generally have congestion, no or very low fever (except for young children) and rarely stomach upset. Flu has high fever, aches, extreme lethargy, sometimes light congestion, and lack of apetite, sometimes stomach upset (rare in adults).

The flu does not need an antibiotic because it is a virus.

If the fever last for 5 days or more, you might be developing a superinfection and need antibiotics, or have a sinus infection that has little muscous production and difficult to get a sample to observe the color.

But, again, since it is confusion between a cold and an allergy I doubt the OP has a fever.

Why would you ask about allergies if you don’t even know if you have any? you probably have some kind of virus, hot tea, good book or movie, cuddly blanket.

You need to go to an allergist and have skin tests done if you don’t even know if you have allergies or not.

@JLeslie
I can only tell you that I am currently getting over a cold. My nose is still running and my stomach has been upset. The mucous has been clear but my body aches .I had the regular flu vaccine and H1N1. I sometimes have an allergic reaction to a cold. I cough for weeks after a cold. I have had congested Airways or mild Asthma.

A cough takes three weeks to clear typically..

Oh alright, thank you all. I think I may have had allergies…
they usually only last from the middle of school til a few hours after I get home.

@eLenaLicious Sounds like you are allergic to something in school.

@philosopher I believe you. If you are prone to asthma you might have more difficulty completely recovering from colds when it goes to your lungs.Some people get stomach upset easier than others, so again, I believe you. Is your nose running a lot, or is it that you have mucous running into your lungs, especially at night, and you wake up coughing horribly?

You can get the flu even if you have had the flu vaccines, but you don’t sound like you have the flu anyway. Flu is very high fever, over 102 typically and you cannot get out of bed.